• Journal of Korea Multimedia Society
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• v.5 no.3
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• pp.323-330
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• 2002

Recently, the existing embedded real-time operating systems(RTOSs) are being developed in terms of various modified versions in every application fields. Major characteristics and difference of these OSs lie in their distinct development of mechanisms which can be used in various environment and task-scheduling function which can control time-limited contingencies. In this paper, we design and implement round/robin scheduling algorithm based on time-sharing with equal-priority for multiple tasks which are provided preemptive and priority task allocation function in $\mu{C/OS-II}$ version 2.03. We propose the most important event-ready list structure in $\mu{C/OS-II}$; kernel, and provide the running result for multiple tasks with equal priority for the proposed structure.

• Bulletin of the Korean Mathematical Society
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• v.59 no.4
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• pp.853-868
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• 2022

We study the structure of right regular commutators, and call a ring R strongly C-regular if ab - ba ∈ (ab - ba)²R for any a, b ∈ R. We first prove that a noncommutative strongly C-regular domain is a division algebra generated by all commutators; and that a ring (possibly without identity) is strongly C-regular if and only if it is Abelian C-regular (from which we infer that strong C-regularity is left-right symmetric). It is proved that for a strongly C-regular ring R, (i) if R/W(R) is commutative, then R is commutative; and (ii) every prime factor ring of R is either a commutative domain or a noncommutative division ring, where W(R) is the Wedderburn radical of R.

• Journal of Sensor Science and Technology
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• v.24 no.1
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• pp.41-46
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• 2015

In this work, pure hierarchical ZnO structure was prepared using a simple hydrothermal method, and Ag nanoparticles doped hierarchical ZnO structure was synthesized uniformly through photochemical route. The reduced graphene oxide (rGO) has been synthesized by typical Hummer's method and reduced by hydrazine. Prepared Ag/ZnO nanostructures are uniformly dispersed on the surface of rGO sheets using ultrasonication process. The synthesized samples were characterized by SEM, TEM, EDS, XRD and PL spectra. The average size of prepared ZnO microspheres was around $2{\sim}3{\mu}m$ and showed highly uniform. The average size of doped-Ag nanoparticles was 50 nm and decorated into ZnO/rGO network. The $C_2H_2$ gas sensing properties of as-prepared products were investigated using resistivity-type gas sensor. Ag/ZnO-rGO based sensors exhibited good performances for $C_2H_2$ gas in comparison with the Ag/ZnO. The $C_2H_2$ sensor based on Ag/ZnO-rGO had linear response property from 3~1000 ppm of $C_2H_2$ concentration at working temperature of $200^{\circ}C$. The response values with 100 ppm $C_2H_2$ at $200^{\circ}C$ were 22% and 78% for Ag/ZnO and Ag/ZnO-rGO, respectively. In additions, the sensor still shows high sensitivity and quick response/recovery to $C_2H_2$ under high relative humidity conditions. Moreover, the device shows excellent selectivity towards to $C_2H_2$ gas at optimal working temperature of $200^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.39 no.9
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• pp.734-740
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• 1995

The primary and secondary structures of Xanthomonas palargonii 5S rRNA were determined. The higher order structure of the 5S rRNA was also analysed using several ribonucleases and chemical probes, such as ethylnitrourea, Pb2+, dimethylsulfate and diethyl pyrocarbonate. Ethylnitrourea was used for probing the phosphate groups involved in the tertiary interactions in the 5S rRNA. Nucleotides G72, A73, G75, A78, G98, G100 and A101 in unstable helical region d, nucleotides C36, C37, A39, and C41 in loop c, nucleotides A29 and G33 in stem C became resistant to ethylnitrourea modification in the presence of Mg2+. On the basis of findings from chemical and enzymatic studies, and also Pb2+-induced cleavages, it was concluded that region b-C and unstable helical region d may act as hinges in the folding of 5S rRNA.

• Proceedings of the Safety Management and Science Conference
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• 2011.04a
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• pp.95-99
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• 2011

The research analyzes structure models of Repeated Measurement Design (RMD) and Hierarchical Design (HD). The experimental unit of RMD model is living organisms, such as human. In contrast, HD is used when all the factors are random. The HD models are derived from R:B:A, R:C:B:A and R:C:($A{\times}B$).

• Kyungpook Mathematical Journal
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• v.56 no.4
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• pp.1207-1235
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• 2016

Let M be a real hypersurface with constant mean curvature in a complex space form $M_n(c),c{\neq}0$. In this paper, we prove that if the structure Jacobi operator $R_{\xi}= R({\cdot},{\xi}){\xi}$ with respect to the structure vector field ${\xi}$ is ${\phi}{\nabla}_{\xi}{\xi}$-parallel and $R_{\xi}$ commute with the structure tensor field ${\phi}$, then M is a homogeneous real hypersurface of Type A.

• Structural Engineering and Mechanics
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• v.39 no.5
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• pp.683-701
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• 2011

In this study, inelastic displacement ratios and ductility demands are investigated for SDOF systems with period range of 0.1-3.0 s. with elastoplastic behavior considering soil structure interaction. Earthquake motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil are used in analyses. Soil structure interacting systems are modeled with effective period, effective damping and effective ductility values differing from fixed-base case. For inelastic time history analyses, Newmark method for step by step time integration was adapted in an in-house computer program. Results are compared with those calculated for fixed-base case. A new equation is proposed for inelastic displacement ratio of interacting system ($\tilde{C}_R$) as a function of structural period of interacting system ($\tilde{T}$), strength reduction factor (R) and period lengthening ratio ($\tilde{T}/T$). The proposed equation for $\tilde{C}_R$ which takes the soil-structure interaction into account should be useful in estimating the inelastic deformation of existing structures with known lateral strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.867-872
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• 2000

A 1:12 scale 10-story RC building structure was constructed and the experiment was performed. The test results are presented and compared with the results of the analysis conducted with DRAIN-2DX. It is concluded that some local deformations cannot be described reasonably with the wall model using only Plastic Hinge Beam-Column Element(TYPE02) in DRAIN-2DX whereas the strength and stiffness of the whole structure can be predicted with high reliability.

• Journal of Korea Foundry Society
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• v.25 no.1
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• pp.30-35
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• 2005

The structures and mechanical property of the unidirectionally solidified Al-Co eutectic alloy were investigated. Al-Co eutectic alloy was unidirectionally solidified with growth rates(R) between I cm/hr and 10 cm/hr in the induction furnace maintaining the thermal gradient (G) at solid-liquid interface, $32^{\circ}C$/cm. The eutectic microstructure was varied with the growth condition(G/R ratio). When the G/R ratio was larger than $8.5{\times}10^{3}^{\circ}C/cm^{2}/sec$, a lamellar structure was formed, But the G/R ratio was smaller than $8.5{\times}10^{3}^{\circ}C/cm^{2}/sec$, a colony structure was formed. It was found that the interlamellar spacing(${\lambda}$) was dependent on the growth rate(R) with the relationship, ${\lambda}^{2}{\cdot}R=constant$. The microhardness of this eutectic alloy increased with increase in the growth rate.

• Journal of the Mineralogical Society of Korea
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• v.16 no.3
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• pp.223-232
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• 2003

The co-precipitation method is applied to synthesize the cathode material Li[L $i_{x}$M $n_{1-x-y}$C $r_{y}$ ] $O_2$ for lithium rechargeable batteries at $650^{\circ}C$ (CR650) and 8$50^{\circ}C$ (CR850), respectively. Rietveld indices indicate that $R_{wp}$ with respect to $R_{exp}$ ( $R_{wp}$/ $R_{exp}$) are 9.2%/10.1% for CR650 and 15.9%/9.76% for CR850, respectively. $R_{B}$ and S (GofF) shows 10.9%, 8.54% and 1.9, 1.6, respectively. Rietveld structure refinement reveals that layer structure of LiMn $O_2$ (R3m) coexists with lower symmetry of Li[L $i_{1}$3/M $n_{2}$3/] $O_2$ (C2/c) due to superlattice ordering of Li and Mn in metal-transition containing layers. Unit-cell parameters are calculated as a=2.8520(2)$\AA$, c=14.248(2)$\AA$, V=100.40(l)$\AA^3$ for CR650, and a=2.8504(1)$\AA$, c=14.2371(7)$\AA$, V=100.179(8)$\AA^3$ for CR850. Final chemistry is obtained as Li[L $i_{0.35}$M $n_{0.56}$C $r_{0.09}$] $O_2$ (CR650) and Li[L $i_{0.27}$M $n_{0.61}$C $r_{0.13}$] $O_2$ (CR850), respectively.y...y..vely.y...y..